Oberg Guitars-An Overview

Every guitar maker and serious guitar player knows a great guitar when they hear one. The qualities that instrument must have in order to be successful are clarity, sufficient volume, power, and projection, a wide spectrum of dynamic responses, balance and separation through the registers, and ample sustain. I think most would not argue with these criteria. For me, one other criterion just as important is that of character. The underlying, or maybe its overlaying character of a guitar is what gives it personality. Every instrument has some character, to one degree or another, that will perhaps be experienced as warmth, openness, sophistication, boldness, or liveliness. These are the qualities that separate an average guitar from a really great one.

I believe clarity to be perhaps the most important aspect of a guitar’s sound. For a guitar to have this each note must consist of a reasonably strong fundamental with a relatively even mix of partials. No overtone should jump out at you; their relative amplitudes must be such that they blend nicely to create a pleasant timbre to each note. Of course strings can either enhance or detract from this quality, but the guitar will have certain tendencies, and those should lean toward a timbre that consists of a not-overbearing fundamental and an even mix of overtones, diminishing in volume as their pitch increases. If the higher overtones are too strong the note will have a bite, a sort of rough edge, as the higher in the overtone series you go the more enharmonic the notes become relative to the fundamental. If the overtones are weak the note will lack character and color, creating more of a dry sound. The question is of course how to achieve this.

My focus is to build guitars that embody this ideal of timbral quality, yet are not so even and neutral that they lack character. They must also satisfy all of the other requirements already mentioned. It is my job to listen to the client, find out which elements of sound they find attractive, and build a guitar to these parameters. As a classical guitar player for 38 years, a composer for 10 years, and previous careers as both a piano technician and furniture maker, I feel I have a natural affinity for this craft.

Over the years I have worked with many bracing patterns. The pattern I am primarily using now is a modified fan system that utilizes three somewhat wide and very low braces, in conjunction with four standard fans. The wide and standard fans alternate from left to right, with a wide one on the centerline. All of the fans notch over the bridge patch, except the outside fan on the treble and the base sides. The center wide fan stops very close to the end block, and the two closing fans at the bottom stop well short of the centerline. Including these two braces, I suppose the system is really a nine-fan system.

The wide braces are crossing a lot of grain, so they are helping to discipline the top. However they are shaped to a very low profile, domed in cross-section, that has its highest part just forward of the bridge. There is not much mass to the wide braces after they are shaped, so their effect is to unify the top in its modes of vibration, without stiffening it up too much. This combined with the open V at the bottom and the two outside braces free from the bridge patch contribute to fullness and openness of sound - one that is amply controlled yet free enough to create plenty of volume.

The regular fans are profiled with their highest points in the same area as the low fans, and are nearly triangulated. These braces drop off substantially in height, terminating in a featheredge. I vary the height and width of these fans depending on the top stiffness and what kind of sound I am going for, but I am always looking for that focus that translates to a unified, even sound with no dead spots on the fingerboard.

Because of the concept of sympathetic vibration there will always be some notes that are reinforced by the open strings more than others. Not every note shares a harmonic strong enough in amplitude to add to its volume. However, if all notes are strong enough without the support of sympathetic vibration then the effect of differing volume between notes will be minimized. This is necessary to achieve evenness throughout the registers. The wide brace system helps create evenness in volume from note to note.

For about four years now I have been using two small auxiliary sound holes in the sides of the upper bout. These are placed 31/4” out from the centerline on either side of the neck. The effect is to open the sound up more-especially for the player. However after playing guitars with this feature for some years now I believe it enhances the instrument’s ability to speak, and to project. The holes are 7/8” in diameter, so they are not so large as to bleed off too much energy. I have experimented with larger holes and various placements and believe the current arrangement to be ideal. To me the greatest advantage of the holes is the greater awareness of nuance and subtlety they afford the player.

I build guitars one or two at a time in my shop in San Marcos, California. I have a ‘dry’ room where I regulate the humidity level, and all of my materials are master grade and well seasoned. I try to keep a guitar once it is finished and strung for one or two weeks-the object of this is to give the guitar a little time to settle in. If necessary I can make minor adjustments that will affect both the sound and the action, before I ship the instrument to the client.

A number of people have been instrumental (no pun intended) in helping forge my career. Ervin Somogyi of Oakland, California gave me my first job working for a luthier, and his influence in my aesthetic and general approach to the craft has been lasting. Ervin has a tremendous eye for line and curve, and a creative and ingenious approach to jig and fixture making. Add to all this his unparalleled dry sense of humor and one can see how a year in his shop would be a valuable experience.

My two years working with Robert Ruck changed my whole concept of the classical guitar. We built some 65 guitars together, and Rob was generous with his practical knowledge of and philosophy about guitar making. His hand tool skills are remarkable, and I was forced to take my own skills to another level. It was in Rob’s shop that I was introduced to both the wide brace concept and the auxiliary sound ports. Though I don’t always use the wide braces, I believe in their efficacy, and am able to control the system to achieve consistent results.

There have also been many guitarists and other musicians who have helped shape my ideas about sound and players’ needs. Listening carefully to their comments, and trusting my own intuition and abilities have been invaluable tools over the years in my growth as a luthier.

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